Mededeelingen omtrent gevoeligheidsproeven van iepen voor graphium ulmi Schwarz, Gedurende 1929 en 1930

METHODS FOR SCREENING AND FOR THE RAPID SELECTION OF ELMS FOR RESISTANCE TO DUTCH ELM DISEASE2

“…The most promising approach to control appeared to be the search for resistant clones of the European elm. It was to the credit of Dr. JOH. WESTERDIJK, that as early as 1928 she draw attention to the possibility of growing elms resistant to Ceratocystis ulmi (Buisman) C. Moreau, the causal factor of the disease (WESTERDIJK, LEDEBOER and WENT, 1931). Originally, trees showing some resistance were selected from the existing elm population and from seedlings imported from different parts of the world (BUISMAN, 1931;WENT, 1938).…”

Fusarium oxysporum colonizes the stem of resistant tomato plants, the extent varying with the R-gene present

“…oxysporum is a soil-borne fungus that infects plants via the roots and colonizes the xylem vessels. F. oxysporum infection causes wilt symptoms, similar to those of other xylem colonizing fungi like Ophiostoma ulmi, the causal agent of Dutch Elm disease (Tchernoff 1965;Westerdijk et al 1931). In the interaction between Fol and tomato, several R-gene -AVRgene combinations have been identified (Table 1).…”

Proceedings of the fourth international workshop on the genetics of host-parasite interactions in forestry: Disease and insect resistance in forest trees

“…There, the first studies were performed on the etiology of the disease that had been killing elms in western Europe since the end of World War I. The causal fungus was firstly isolated by Dina Spierenburg (Buisman 1921), then described and named by Marie B. Schwarz (Schwarz 1922); later followed by the development of a reliable inoculation method by Christine Buisman (Westerdijk et al 1931). The path-breaking research conducted by the two latter scientists-both of whom were working at the aforesaid Laboratorium-constituted the fundamental requisite for starting up a breeding program (Holmes 1993).…”